FUNCTIONAL ELECTRICAL-STIMULATION (FES) - MUSCLE HISTOCHEMICAL ANALYSIS

Functional electrical stimulation (FES) has been used in Brazil since 1989 to obtain functional improvement in paraplegic patients' orthosta sis and locomotion. The aim of this paper is to evaluate the histochem ical changes observed in the quadriceps femoris muscle following -the use of FES. We studied four patients with traumatic spinal cord lesion s at T4-10 level, Frankel A, all within 12-24 months postlesion. They were all submitted to FES using the following criteria: square-wave, 2 0-30 Hz frequency, pulses of 0.003 seconds, time of stimulation 5 seco nds, resting interval 10 seconds. The stimulation was applied during 9 0 consecutive days, 30 minutes each time, twice daily. The interval be tween the stimulations was 6 hours. Quadriceps muscle biopsies were pe rformed before and after the use of FES. We used ATPase technique for the histochemical analysis, where three different dying patterns can b e observed for the three types of muscular fibres (I, IIa and IIb). Th e two samples from each patient were analysed measuring the fibres' di ameters and their index of atrophy, and counting the total number of e ach type of fibre in each sample. The mean total number of fibres in e ach sample was 256 +/- 12.3. The results showed that the sizes of the three types of fibres were not modified with the use of FES; the numbe r of type IIa fibres increased in a significant fashion, after using o f FES.